The amount of wireless data being transferred is increasing. Cellular communications systems may utilize licensed spectrums (Bands), where transmissions are tightly controlled by a network. Unlicensed bands may be used for cellular transmissions along with licensed bands. Unlicensed bands may be less reliable, because of the presence of interfering transmissions from other standards, such as wireless local area network (WLAN), WiFi, Bluetooth, and cordless phones (digital and analog), which transmissions cannot be controlled by cellular nodes.
A wireless system may use a licensed spectrum component, e.g. a cellular system, such as Long Term Evolution (LTE), and an unlicensed spectrum. Carrier aggregation (CA) facilitates user equipments (UEs) receiving signals on two or more carriers.